Which statements describe polyatomic ions? check all that apply.

a)polyatomic ions have many charges.
b)polyatomic ions have one overall charge.
c)polyatomic ions repel other ions to form ionic bonds.
d)polyatomic ions attract other ions to form ionic bonds.
e)polyatomic ions are made up of only one type of atom.
f)polyatomic ions are made up of two or more types of atoms.

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?